Updates from the 2016 San Antonio Breast Cancer Symposium
Thousands of cancer doctors, researchers and patient advocates are in San Antonio, Texas, for the 2016 San Antonio Breast Cancer Symposium (SABCS), December 6 through 10. And, of course, those patient advocates included representatives from LBBC to hear the latest news about breast cancer treatment, research and care.
Our writer and content coordinator, Erin Rowley, is attending this year’s oral presentations. Below, you'll find her reports on a few of the most interesting studies.
Highlights from Wednesday, December 7
Aromatase Inhibitors
The most common type of breast cancer is called hormone receptor
-positive, and it grows in response to the hormones estrogen, progesterone, or both. This type of breast cancer is treated with hormonal therapy, which limits estrogen or changes the way the body responds to it. Aromatase inhibitors (AIs) are a type of hormonal therapy used in postmenopausal women.
Recent research has looked at how long to give a hormonal therapy for premenopausal women, called tamoxifen, in early-stage disease. That research suggests tamoxifen may be better at lowering the risk of cancer metastasizing, or returning elsewhere in the body, when taken for 10 years instead of the standard 5 years. Doctors want to know if aromatase inhibitors would also work better if given for longer than the usual 5 years.
A few studies presented Wednesday morning looked at this issue. One was the phase III DATA trial. It recruited postmenopausal women with early-stage, hormone receptor-positive breast cancer who already took tamoxifen for 2-3 years. Researchers then gave the women either 6 years of treatment with the AI anastrozole (Arimidex) or 3 years of that AI plus 3 years of a placebo.
A phase III study called IDEAL was also presented. It recruited postmenopausal women with early-stage, hormone receptor-positive breast cancer who had already had 5 years of hormonal therapy. (For most women, that hormonal therapy was an aromatase inhibitor.) The participants then randomly got 2.5 or 5 years of the AI letrozole (Femara).
A similar study, NSABP B-42, also recruited postmenopausal women with hormone receptor-positive breast cancer who had already had 5 years of hormonal therapy. The participants then received 5 years of the AI letrozole or 5 years of a placebo.
These three studies found little difference in outcomes between those who had longer or shorter treatment with aromatase inhibitors. None of the trials’ results suggest longer treatment with AIs would benefit the most postmenopausal women with early-stage, hormone receptor-positive breast cancer. More research is needed, but these studies do suggest extended AI therapy could help certain subgroups, such as those with a high risk of recurrence.
For Metastatic Disease
But what if you’re postmenopausal and have hormone receptor-positive, HER2-negative metastatic breast cancer that doesn’t respond to AIs? Researchers with the phase II PrECOG 0102 trial gave some participants the hormonal therapy fulvestrant (Faslodex) plus the targeted therapy everolimus (Afinitor). Other participants got fulvestrant plus a placebo.
Those who got both medicines went a median 10.4 months without the cancer growing, more than twice as long as the 5.1 months for those in the fulvestrant-only group. But, noted Debu Tripathy, MD Wednesday night at a session for breast cancer advocates, these medicines haven’t yet been shown to lengthen people’s lives.
Genetic Mutations
The subject of genetic mutations was popular at SABCS this year. Learning whether you were born with a gene mutation that raised your risk of breast cancer can help you and your doctors learn more about the cancer and plan your treatment.
One trial presented Wednesday looked at data from 60,000 women with breast cancer who had genetic testing. Nine percent of the women had mutations. Researchers identified 12 genes that were significantly associated with breast cancer – 9 associated with moderate breast cancer risk and 3 associated with high breast cancer risk.
The high-risk genes were:
The moderate-risk genes included:
- ATM
- BARD1
- CH1
- MSH6
- NF1
- PTEN
- RAD51D
- TP53
Knowing more about which genetic mutations raise the risk of breast cancer and by how much they raise that risk will continue to help doctors and people with breast cancer make decisions about their treatment in the future.
The POSH trial also looked at genetic mutations. It asked if BRCA mutations affect how long women who are diagnosed with breast cancer at age 40 or younger live after diagnosis.
It found no significant difference in survival between women who did or did not have a BRCA mutation. In women with triple-negative breast cancer, those with BRCA mutations were 11 percentage points more likely to survive than those without a BRCA mutation. That TNBC finding was not statistically significant though, which means it could have happened by chance.
Highlights from Thursday, December 8
Thursday’s most interesting oral presentations looked at a range of topics, including how radiation therapy affects the success of different types of breast reconstruction surgery, and if pertuzumab could work well in treating people with triple-positive metastatic breast cancer.
Radiation and Reconstruction
Many women have their breast(s) reconstructed after surgery for breast cancer. Many women also have radiation therapy after breast surgery, to lower their risk of recurrence. But radiation after reconstruction can make complications more likely and can affect how the reconstructed breasts look.
The MROC study looked at the impact of radiation therapy on reconstruction complications and on how pleased women reported being with their reconstructive surgery. Researchers looked at 2,014 women who had reconstruction either with implants or with their own tissue (skin, fat or muscle from another area of their body) after breast cancer surgery. Reconstruction using tissue is called tissue or flap reconstruction, and more formally called autologous reconstruction.
Of the 2,014 women, 553 had radiation therapy after reconstruction and 1,461 didn’t.
The study found that women who had radiation and implant reconstruction were 2.64 times more likely to have a complication within 2 years. But it found no increased risk for women who had radiation therapy and flap reconstruction. It also found that women who had flap reconstruction followed by radiation were happier with their results than women who had implant reconstruction followed by radiation.
The researchers say this information should help women make informed decisions about radiation therapy and reconstruction.
Triple-Positive Breast Cancer
Breast cancer that is estrogen receptor-positive, progesterone receptor-positive AND HER2-positive grows because of the hormones estrogen, progesterone and the HER2 protein. This type of breast cancer is sometimes called triple-positive.
Doctors know combining the anti-HER2 targeted therapy trastuzumab (Herceptin) with a type of hormonal therapy called an aromatase inhibitor works better than an aromatase inhibitor alone in triple-positive metastatic breast cancer. They also know combining another anti-HER2 targeted therapy called pertuzumab (Perjeta) with trastuzumab and chemotherapy works better than trastuzumab plus chemotherapy in HER2-positive metastatic breast cancer.
Based on that knowledge, researchers with the phase II PERTAIN trial wanted to try a new combination for triple-positive metastatic disease: pertuzumab, trastuzumab and an aromatase inhibitor. They randomly assigned 258 postmenopausal women with triple-positive metastatic or locally advanced breast cancer who hadn’t had systemic, or full-body, therapy in the past, other than hormonal therapy, to one of two groups: the treatment group and the control group. The treatment group received
- Trastuzumab
- Pertuzumab
- An aromatase inhibitor, either anastrozole (Arimidex) or letrozole (Femara)
The control group received trastuzumab and an aromatase inhibitor, but not pertuzumab.
The researchers found that adding pertuzumab delayed progression by about 3 months. Median progression-free survival (PFS), the time from starting treatment to progression or until the treatment caused too many severe side effects, was about
- 18.9 months in the group that got pertuzumab, trastuzumab, and an aromatase inhibitor
- 15.8 months in the group that didn’t get pertuzumab
Serious side effects were experienced by 33.1 percent of the group that received pertuzumab and 19.4 percent of those in the non-pertuzumab group. The most common side effects in both groups were diarrhea, hair loss and nausea.
In a session for advocates on Thursday night, Hyman Muss, MD called the results “not ready for primetime,” but promising. More research with larger groups of people needs to be done to confirm the findings.
Highlights from Friday, December 9
Hair Loss
Alopecia, or hair loss, is a common side effect of breast cancer treatment. It can be one of the most upsetting parts of cancer therapy. Many women feel losing their hair makes their cancer status public.
Doctors and women with breast cancer are interested in therapies that could prevent hair loss during treatment. Scalp cooling is one promising approach. Studies suggest keeping the scalp cold while giving chemotherapy may stop hair from falling out.
Last year, the FDA approved the first device of this type, called the DigniCap scalp cooling system. U.S. research on that system found about 70 percent of women who used the device kept at least 50 percent of their hair.
The Scalp Cooling for Alopecia Prevention (SCALP) trial tested a different scalp-cooling device, called the Orbis Paxman Hair Loss Prevention System (OPHLPS). Researchers wanted to know if the device was safe, comfortable and worked to prevent hair loss in women getting chemotherapy for early-stage breast cancer.
The researchers randomly assigned 182 women to use the OPHLPS scalp-cooling device before, during and after receiving chemotherapy; or to get chemotherapy without using the device. The women all had stage I or II breast cancer and were scheduled to receive chemotherapy for at least 4 weeks, with either a taxane or an anthracycline. This was an important difference from the research that led to the other scalp-cooling system, the DigniCap, being approved. In the U.S., that research was almost entirely limited to taxanes. Another difference: the earlier research wasn’t randomized, and this study was. Studies are considered more reliable when participants are randomly assigned to different groups.
The researchers defined the device as successful in cases where a woman lost 50 percent or less of her hair. By this measure, the device was successful for about half the women who used it. But all the women in the other group lost more than 50 percent of their hair. The device was more successful in women who got taxane chemotherapy than in women who got anthracycline chemotherapy. About 65 percent of women who used the device and had taxane chemotherapy kept their hair, vs. about 22 percent of women who used the device and had anthracycline chemotherapy.
Fewer than 15 percent of participants reported the device was uncomfortable. Side effects were mild. The most common ones were headache, nausea and dizziness.
Most people have chemotherapy for longer than the 4 weeks that have so far been reported in this study. It’s possible hair that didn’t fall out during the first 4 weeks could fall out later. The researchers plan to report on that once more time goes by.
There have been concerns in the past that this type of therapy could increase the risk of breast cancer spreading to the scalp. Past studies show this is unlikely, but the researchers will continue to monitor that possibility.
The company that makes the device is seeking FDA approval based on the results of this study.
Join us for our webinar, News You Can Use: Annual Update from the San Antonio Breast Cancer Symposium, Dec. 14 at noon ET. During this program, our expert Melinda Telli, MD will talk about research presented at the conference and what it means for you. She’ll also answer your questions during a Q&A.
To get live updates, follow LBBC on social media using the hashtag #LBBContheBeat.
